Aventis to sell CropSciences to BASF, Bayer UPDATE 1-Aventis to sell CropSciences to BASF,Bayer-source PARIS, June 29 (Reuters) Franco-German life sciences firm Aventis is close to selling its CropScience unit in two parts to German chemical firms Bayer and BASF, a source close to the deal said on Friday. The source said Aventis is negotiating to sell Aventis CropSciences' insecticide business to BASF, and with Bayer to take over the rest. No deal has yet been signed. Aventis has been seeking to sell off CropSciences, the world's second-biggest agrochemical business, to focus more closely on pharmaceuticals, in line with its sector peers. U.S. firms Dow Chemical, Monsanto and DuPont were also initially interested in CropSciences, but pulled out of the running. Aventis CropSciences' insecticide operations had 2000 turnover of 1.041 billion euros ($882.2 million). The world leader in its field, it had 14 percent of market share, compared with 12 percent for Bayer and seven percent for BASF. CropSciences also has interests in herbicides, with a 10 percent market share, against 14 percent for BASF and three percent for Bayer. It also has fungicide, environmental sciences and seed businesses. In Germany, BASF and Bayer declined to comment on the news. Analysts value Aventis CropScience, in which Germany's Schering AG owns 24 percent, at 7 billion-8 billion euros. Aventis's exit from its agrochemical business, announced about five months ago, will allow Aventis to refocus on its pharmaceutical business, as Novartis and AstraZeneca are doing. Aventis CropSciences turnover slipped to 4.034 billion euros in 2000, down from 4.060 billion in 1999, hurt by poor market conditions and climatic factors. Its gross margin, however, improved by 3.5 points to 50.4 percent.